Mac Pro may find work as successor to Xserve

Thursday, January 9, 2014

By John Rizzo

Apple's new Mac Pro has high-end workstation users drooling, but others are eying the diminutive powerhouse as the successor to the old Xserve Mac server. And Apple appears to have given an oblique blessing to at least one company who has figured out how to rack-mount the 10-inch Mac Pro cylinders. But how well suited is the Mac Pro to function a server?

Since the discontinuation of the Xserve in 2011, Mac-friendly IT administrators have not had server hardware from Apple that would fill the Xserve's enterprise niche. Mac minis have a place (and Apple sells a version with Server preconfigured), but are not very powerful, particularly if you are running all of the services available in OS X Server. The previous Mac Pro was powerful, but its bulky tower configuration and awkward size made it impractical to mount in a rack.

The new Mac Pro offers a processor used in servers by Dell and other server makers, doesn't generate a lot of heat, and sits in a diminutive 10-inch by 6-inch cylinder. You could fit 9 new Mac Pros in the space taken up by 3 Xserves, roughly one-third of the space. But how would you store them in a rack?

A Mac mini hosting company, MacStadium, has come up with a solution. Their rack holds 270 Mac Pros in 12 square feet of floor space -- more server power than could typically be housed in the same space with conventional server hardware. So far, MacStadium is only offering to host or collocate Mac Pros at its facilities, and hasn't yet made the rack available.

The question arises as to whether Mac Pros mounted in MacStadium's rack can be properly cooled. The rack will mount the Mac Pro cylinders are their side and cool them with a horizontal flow of air. This is at odds with the way Apple has demonstrated the Mac Pro's design, which has a central shaft through which air rises to cool the cylinder, with heat escaping at the top.

Last week, Apple seemed to settle this question by quietly posted a tech support document called "Using the Mac Pro (Late 2013) on its side" that blesses to MacStadiums' Mac Pro rack-mounting strategy without mentioning racks or servers or why you would position the Mac Pro sideways:

The Mac Pro (2013) has a fan system capable of cooling the computer in a vertical or horizontal orientation as long as you follow these guidelines:

Provide enough space at each end of the computer for unrestricted airflow into the base and out the exhaust at the top. Make sure that the air intake and exhaust ports are not covered.

When using multiple Mac Pro (Late 2013) computers, do not direct the exhaust at the top of one Mac Pro towards the intake of another system. Place the computers side by side with a gap of at least several inches between them.

So far Apple has not promoted using the Mac Pro as a server, but it seems clear with this tech support article that Apple is giving the green light to rack mount it. It's also clear from the second point that horizontal mounting is the preferred way that the Mac Pro could be rack mounted and still be properly cooled. And, there is no earthly reason you would want to sit the Mac Pro on its side if you're using it as a workstation. (Visions of the $3000 cylinder rolling off a desk come to mind.)

It seems that Apple wants people to use the Mac Pro as a server but doesn't want to say it out loud.

The Mac Pro is certain not a machine that's designed to be a server. Aside from the shape, the starting $3,000 configuration comes with two graphics cards that are completely unnecessary in a rack-mounted server, as is the ability to run three monitors. Also of no server use is the preinstalled content production software, Final Cut Pro, Apeture, and Logic Pro X. But as I've previously reported, Mac Pro buyers aren't paying a premium over other PCs with similar hardware.

But other aspects of the Mac Pro hit the mark. The Intel Xeon E5 processor is a server-grade CPU used in other servers. The base configuration is a quad-core processor, with options for 6, 8, and 12 cores.

The storage configuration of the Mac Pro is well suited for use in a data center. The only internal storage is fast, flash-based storage, starting at 256 GB up to 1 TB -- enough to host the operating system and key server software. The lack of the ability to add additional internal storage is not a drawback, as servers often use Network Attached Storage or Storage Area Networks (SAN) systems that use Fibre Channel, which can that Mac Pro can connect to through one of the six high-speed Thunderbolt 2 ports. There are also now Thunderbolt 2-based RAID systems available.

The enterprise server market was never large for Apple, which is why it discontinued the Xserve. But for those believers who want a Mac-based enterprise server, or even a server farm, the 2013 Mac Pro will probably be generating interest.